US678674A - Crucible-furnace. - Google Patents

Description

No. 678,674. Patented July I6, I90L.

' 0. MICHAEL.

I GRUCIBLE FURNACE. (Application fllad June 14', 1901. (No Mode lhvrrnn STATES nrnr rrrcn.

OTTO MICHAEL, OF FREIBURG, GERMANY.

CRUCIBLE FURNACE.

SPECIFICATION forming part of Letters Patent No. 678,674, dated July 16, 1901. Application filed June 14, 1901. Serial No. 64,502. (No model.)

To all 2071 0121, it may concern.-

Be it known that I, OTTO MIcHAEL,foundryforeman, a subject of the Grand Duke of Baden, residing at Guntramstrasse 36, Freiburg, in the Grand Duchy of Baden and Empire of Germany, have invented certain new and useful Improvements in Crucible-Furnaces, of which the following is a full, clear, and exact description.

In the whole industry of metal founding, and especially in the construction of cruciblefurnaces, a great many novelties have been introduced from time to time. They have been mostly of such an unpractical nature, however, that they have had to give wayto the old processes-the crucible,cupola,and reverberatory furnacesnotwithstanding that it has always been clear to those engaged in such industry that the old crucible-furnaces, which do not change the chemical composition of the smelting charge to any appreciable degree, work very unprofitably by reason of their great consumption of fuel.

It has been proposed, for instance, to place several crucibles in one furnace or to set crucibles in fines a certain distance above the floor of the furnace for heating the mass where the heat of the waste gases may be utilized; but even in these methods a large and continuous consumption of fuel is imperative, otherwise the heat will be insufficient.

It is well if a really workable smelting plant is to be set up to start from the basis of utilizing the heat of waste gases before it escapes farther into the fines leading to the stack without the heated crucibles being placed in the oven for a second heating period. This is the purpose and subject-matter-of the present invention, according to which the crucibles to be heated are placed within niches provided in the mouths of the flues in the furnace on the same level as the usual grating or floor, and the material contained in them becomes melted even at the first period of warming, no matter whether it is not readily fusible or otherwise, so that the contents of the crucible may be poured out immediately after the first melting period, together with those crucibles that have passed through their second melting period.

Upon the accompanying sheet of drawings is shown the means for carrying out my in vention.

Figure 1 is a vertical section through the line A B of Fig. 2, and Fig. 2 a horizontal section on line O D of Fig. 1.

The horizontal section of the crucible-chamber a of the oven is shown quadrilateral in Fig. 2; but it may be of any other shape. In the middle of each of the four walls is built a niche of curved form 1), four in all. These niches Z) are of convenient height, so that crucibles or melting-pots 0, provided with covers d, can stand therein upon suitable bases e, the crucibles being introduced through the crucible-chamber a into the niches l) at the mouths of fines f, which form a continuation of the niches b, and removed by the same way.

The floor of the crucible-chamber a is made ofagrating g, composed, preferably, of rectangular section-bars. Beneath and across the bars of the grating are two double T- girders h or a frame of similar section, which convey to the brick wall 2' of the furnace the weight of the filled crucibles 13 standing on the grating g. Underneath the grating g is an ash-pit it, easily reachable and readily cleaned. Opening into the outer walls of the niches b somewhat, as shown in Fig. 1, are channels lat a suitable height above the crucibles 0, leading from the tines into the stack. It is advantageous to let the individual branch channels Zlead into a common flue n built in the wall 2' of the furnace around the crucible-chamber 0; before finally leading into the main flue, by which arrangement the draft from the individual channels Z can be equalized. For the purpose just mentioned it is advisable to make the main flue terminate at different points-for example, at two points in the flue n, as shown by Fig. 2.

The surfaces of thefurnace that come in direct contact with the fire are preferably covered with dolomite, ganister, or like suitable material.

The above-mentioned operation takes place in the crucible-furnace according to the present invention as follows: Supposingthefour crucibles p standingin the middle of the crucible-chamber a to be taken out (together with the molten material contained therein) and the lid q (made of stone, &c.) removed and the interior of the shaft thus exposed, the crucibles c,which were heated during the last smelting, so as to melt the greater part of the contents, are then taken out one by one, while other crucibles 0, containing fresh uninelted material, are put in place thereof into the niches b. The crucibles c, which have just been removed from the niches b after their first heating, are now assembled in the places previously occupied by the crucibles p, as shown in the drawings, in the center of the crucible-chamber a, Where they remain for the second heating. The space in the crucible-chamber a between the separate pots or crucibles p is filled up with coke, which done the second heating begins.

What I claim, and desire to secure by Letters Patent, is

1. A crucible-furnace comprising a crucible-chamber, niches in the walls of the chamber for the reception of crucibles to be preheated, channels leading from the outer walls of the niches, and means for heating the furnace. V

2. A crucible-furnace comprising a crucible-chamber, niches in the walls of the chamber for the reception of crucibles to be pre-- heated, channels leading from the outer walls of the niches, a main fiue surrounding the chamber and common to all the channels, and means for heating the furnace.

3. A crucible-furnace comprising a crucible-cha1nber, means for heating the furnace having a grate, niches in the walls of the chamber for the reception of crucibles to be preheated, having floors on the same level as the grate and channels leading from the outer walls of the niches.

In witness whereof I subscribe my signature in presence of two Witnesses.

OTTO MICHAEL.

Witnesses:

GEORGE SCHMITT, CHRISTIAN WEILBRENNER.

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